Subtracting, worked out

The Borrow Bank

When a column comes up short, you borrow from next door. Every trade gets crossed out and written above, so you can see exactly where the ten came from.

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Start with
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Take away
Make a problem for me — pick what goes in it

Try

The work

Say it out loud

    Borrowing isn’t cheating — one ten is worth ten ones, so you’re trading, not taking.